Weft selection mechanism for looms



1 F. DAVIES ETAL WEFT SELECTION MECHANISM FOR LOOMS April 23, 1957 Filed July 21, 1953 FIG.

S m m W m Kmm mmk RD FEH Rm W mm 1 M United States Patent WEFT SELECTION MECHANISM FOR LOOMS Frank Davies, Manchester, John Frederick Moseley, Heaton Mersey, Stockport, and Iorwerth Hefin Thomas, Manchester, England, assignors to The British Cotton Industry Research Association, Didsbury, Manchester, England, a British research association Application July 21, 1953, Serial No. 369,358 Claims priority, application Great Britain August 1, 1952 7 Claims. (Cl. 139-233) This invention relates to weft selection mechanisms for looms of the kind having a drop box motion with at least two shuttle boxes at one side and a single box at the other side with change release mechanism including complementary compartments for storage of the change members and including at the drop box side an electrically operated feeler mechanism for each shuttle box connected to control means for releasing change members from each complementary compartment and to locate same at a transfer position to await return of the operative shuttle, the weft selection mechanism also having signal storing means for delaying or storing the signal from the said feeler mechanism and releasing same at the required time, and means for triggering the change release mechanism when the operative shuttle, i. e. the shuttle from which the signal has been obtained is returned to the single box side of the loom.

The expression change release is used herein to include shuttle or bobbin change release, while the term change member is used to define the shuttle or bobbin released thereby, as the case may be, while the expression bobbin is used to define either a pirn or a cap.

The object of the present invention is to provide an improved construction of Weft selection mechanism.

According to the invention a weft selection mechanism for a loom of the kind referred to comprises by a series of trip levers, one for each shuttle box of the drop box, mechanism connecting each lever to the change release mechanism of the complementary compartment of the magazine, electric means operated by each bobbin feeler mechanism for moving the complementary lever to an operative position according to which shuttle is approaching exhaustion, and actuating mechanism associated with the bottom shaft of the loom and engageable with whichever trip lever is in the operative position to release a change member in the complementary compartment for movement to the said transfer position whereby any particular shuttle box of the drop box will only receive change members from a particular compartment of the magazine.

The invention may be further characterised by a single cam adapted to operate any one of the trip levers as each one is moved to the operative position; or in that the cam operates on each trip lever through a bell-crank lever, one end of which has a roller follower adapted to engage the cam periphery whilst the other end is adapted to engage the trip lever when the latter is in the operative position; or by signal storage means wherein each trip lever is moved against a returning force e. g. gravity from one inactive position to a second inactive position on operation of the electric means by the bobbin feeler mechanism, catch means for locating the trip lever in an operative position between the two inactive positions on release of the trip lever from the second inactive position, said release being effected in timed relation with the other moving parts of the loom by movement of the shuttle box to carry the shuttle from ice which the signal has been obtained out of contact with the bobbin feelers of its feeler mechanism.

According to a preferred embodiment for aloom having bobbin-change mechanism the weft selection mechanism comprises a trip lever for each compartment of the drop box, electro-magnetic mean for moving each lever against a returning force e. g. gravity from an inactive position of rest past an operative position to, and holding it in, a second inactive position, said electromagnetic means being connected to an electric bobbin feeler sensitive to an almost empty bobbin and catch means adapted to be reset by actuation of the trip lever, for positioning the trip lever in its operative position immediately preceding the entry of the shuttle with the almost empty bobbin to the single box whereby the trip lever is returned after actuation to its first inactive position.

In the drawing filed herewith:

Fig. 1 illustrates in side view one example of a weft selection mechanism constructed in accordance with the invention and which is applicable to a two by one drop box loom picking two and two;

Fig. 1A is a fragmentary view of part of the mechanism shown in Fig. 1;

Fig. 2 shows schematically how the improved pirn selection mechanism is interconnected to the weft feeler mechanism.

In Fig. 1 of the drawing only as much of the loom is included as is necessary for the understanding of the in vention, and as illustrated therein the weft selection mechanism comprises a trip lever 10 for the upper shuttle box of the drop box mechanism, said trip lever being operated from the pirn feelers i1, 12 through a coil 13 of a 24-volt solenoid operating on the armature 14-. The pirn feelers 11, 12 are so located at the drop box side of the loom that they can feel the pirn in the upper shuttle box when the latter moves to its upper position. Pirn feelers 15, 16 similar to feelers 11, 12 are adapted to feel the pirn 17 (Fig. 2) in the lower shuttle box of the drop box as the latter moves to its lower position, and similarly operate a second trip lever, but said lever and the solenoid and connecting links associated therewith are omitted from the drawings.

The trip lever 10, which together with the second trip lever is located at the single box side of the loom, is disposed in a substantially horizontal position and one end thereof is pivotally attached at 18 to one limb of a bellcrank lever 19, the other limb being pivotally attached to a socket 20a on the end of a vertical rod 20 adapted to move vertically against the action of a return spring 21. The rod 20 is attached by links (not shown) to the release mechanism 2011 of one of the vertical compartments of the bobbin magazine. A pivoted catch 22, loaded so as to rotate in a counter-clockwise direction by a spring 23, supports the trip lever 10, an adjustable screw 24 forming a limit stop for the catch. The trip lever 10 has a portion of its lower edge cut-away to provide a step between faces 10a and 10b which faces enable the catch to support said lever in two alternative positions.

Mounted on the bottom shaft A of the loom (each revolution of which is equivalent to two picks), is a cam 25 having a roller follower 26 mounted on an axle 2'? at the end of one limb 2B of a bell-crank lever 2Q pivoted at 30. The substantially vertical limb of the bell-crank lever 29 consists of two arms 31 to which is secured a cross bar 32 adapted to engage the free end of the trip lever 10 for a purpose to be explained later. The said bell-crank lever 29 has a downward extension 33 for attachment of a tension spring 34 whose function is resiliently to load the follower into contact with the cam periphery.

As will be seen from Fig. 2 of the drawings, the trip lever 10 is adapted to'be located in three alternative'positions, (a) a lower inoperative position, illustrated by dotted lines, (b) an upper inoperative position indicated by chainlines, and (a an operative position mid-way be} tween the two inoperative positions and indicated'by full lines 'The' moveme nt of the trip lever togetherwith the ass'b'ciatedmechanism to bring such lever from position (and position (b) constitutes a signal storage means for the signal received from the felt pirn as will'be clear from the following: h 1

Presume the shuttle associated with the upper shuttle box has a'pirn or bobbin wound with S twist weft, whilst that associated with the lower box has a pirn wound with twist weft, and'suppose the S shuttle, which needs replenishment is'in the top box, and "requires a new pirn whenit next arrivesin the single box. As the shuttle box movesvertically to the top position so that the S shuttle isv in the inoperative position the pirn feelers 11, 12 will enter the said box and will be connected together through the metal sleeve on the base of the almost empty pirn. The coil 13, thus energised, causes the armature Mto be drawnupwards taking with it the trip lever 10 from the dotted-line position (a) to the chain line posi tion (b), Figs. 1 and 2, thereby pivoting same from the lower inoperative position (a) to the upper inoperative position "(b) (see Fig. 2). It will be seen that when the trip lever 10 is in the upper inoperative position (b), the cross bar 32 on the bell-crank lever 29 oscillates virtually in a horizontal plane under the action of cam 25, and will pass beneath the trip lever without acting upon it in any way. Further the upward movement of the trip lever allows catch 22 to pivot to the extent allowed by the step 24 to the position shown in full lines in Fig. 1. Stop 24 is positioned to abut against the frame of the mechanism (not shown) to prevent the complete rotation of the catch 22.

When the shuttle box moves downwards, the circuit through the solenoid is broken, and the trip lever 10 now falls on to the top of the catch 22 and is thus located in the operative position indicated after operation in full lines, Fig. 2. As the S shuttle is about to leave the 2-box side of the loom, the bell-crank lever 29 is rocked by the cam 25 and the cross bar 32 engages the end of the trip lever and moves it forwardly to the full line position, Fig. 1. This movement of the trip lever is transmitted through bell-crank lever 19 and vertical rod 20 to the bobbin-changing mechanism whereby the next full pirn is released from the magazine compartment containing the 8 pirns, the released 8 pirn being allowed to fall to the transfer position and the hammer primed so that when the shuttle arrives at the single box side, the transfer mechanism is ready to replenish the exhausted shuttle when the slay reaches the front dead centre.

The cam 25 is shaped at 25a to provide a period of rest or dwell with the follower engaging the cam and the spring 21 of the rod 20 in compression, and the trip lever remains almost at rest at its extreme forward position with the catch supporting the'edge 10a throughout the period of engagement of roller 26 with cam portion 25a. The dwell on the cam finishes at 2517 and as-a result of the local peak 250 on the cam face, a still further small, but sharp forward movement is imparted to the trip lever 10 to free the latter momentarily from contact with the cross bar 32 and so that the step 100 is carried beyond the end of the catch 22. The lever 10 then falls by gravity until the face 101; rests on the catch 22 and by this time the slay has passed its extreme forward position. This downward movement of the trip lever 10 return-s it to the lower inoperative position and the assembly, of which trip lever it forms part, is reset by action of spring 21, the cross bar 32 moving away from contact with the trip lever as a result of the cam follower falling onto the portion 25c of the cam as the trip lever returns rearwardly to the initial lower inoperative posi-' the return tion indicated by dotted lines, Fig. 2. This rearward movement of the trip lever'10' moves the catch 22 by means of the step 100 between faces 10a and 10b to its inoperative position ready for the next change sequence.

It will be appreciated thatthe mechanism above described is duplicated with respect to the lower shuttle box and is interconnected to theother or Z compartment of the magazine; the cross bar 32 is adapted to engage either oftwo trip levers, but it is onlyv when one or other of the trip levers is in'the'operative position that it is moved to instigate setting of the pirn changing mechanism.

In the example above described, it is impossible to signal a change and then insert the incorrect pirn in the shuttle.

The mechanism for supplying and inserting the bobbins in the shuttles is well known in the trade, and forms no part of the present-invention, and consequently has not been included in the drawings.

What We claim is:

l. A weft selector mechanism for a loom having a drop box motion with at' least two shuttle boxes each carrying a shuttle'at one side and a single box 'at the other side with change release mechanism including complementary compartments-for storage of 'the change members and including at the drop box side an electrically operated bobbin feeler mechanism for each shuttle box connected to control means for releasing change memhere from each complementary compartment and to locate same at-a transfer position to await return of the shuttle, the weft selection mechanism also having signal storing means for delaying or storing the signal from the said bobbin feeler mechanism and releasing same at the required time, and means for triggering the changing mechanism when the shuttle from which the signal has been obtained is returned to the single box side of the loom, said weft selector mechanism comprising at least two trip levers, one for each shuttle box of the drop box, mechanism connecting each lever to the change member release mechanism of the complementary compartment,

electric means operated by each bobbin feeler mechanism for moving the complementary lever to an operative position according to which shuttle is approaching exhaustion, and actuating mechanism associated with the bottom shaft of the loom and engageable with whichever trip lever is in the operative position to release a change member in the complementary compartment for movement to the said transfer position, whereby any particular shuttle box of the drop box will only receive change members from a particular compartment.

2. A weft selector mechanism according to claim 1, further characterised that the actuating mechanism comprises an oscillating cross bar and a single actuating cam, said cross bar being adapted to operate on any one of the trip levers as it is moved to the operative position.

3. A weft selector mechanism according to claim 2, further characterised in that the said cam operates on each trip lever through a bell-crank lever, one end of which has a roller follower adapted to engage the cam periphery whilst the other end carries the cross bar to engage any one trip lever when in the operative position.

4. A weft selector mechanism according to claim 1 further characterised in that the signal storage means comprises mechanism for moving each trip lever against a returning force e. g. "gravity from one inactive position to a second inactive position on operation of the electric means by the weft feeler mechanism, catch means for locating the trip lever in an operative position intermediate the two said inactive positions on release of the trip lever from its second inactive position, said release being effected in timed relation with the other moving parts of the loom by movement of the shuttle box to carry the shuttle from which the signal has been obtained out of contact with the bobbin feelers of its feeler mechanism and into a position for re-use of said shuttle.

5. In a loom having a movable drop box on one side thereof, a weft selector mechanism comprising, in combination, bobbin release means for replacing an empty bobbin on the other side of the loom; movable operating means for actuating said bobbin release means and being movable between an operative position for effecting a bobbin release and an inoperative position, said operating means tending to move to said inoperative position; actuating means arranged reciprocable along a predetermined path; drive means for reciprocating said actuating means in a predetermined sequence with the drop box movement; a trigger means movable between an operative position located between said operating means and said actuating means in the path of the latter, and at least one inoperative position located outside of said path of said actuating means; electro-magnetic shifting means for shifting said trigger means between said positions of the same, and including an electric circuit; and feeler means located on said one drop box side of the loom and including contact means connected in said circuit and adapted to be closed by an empty bobbin in the drop-box whereby said electro-rnagnetic shifting means are actuated to shift said trigger means into said operative position so that said actuating means move through said trigger means said operating means to said operative position of the same so as to effect a bobbin release.

6. In a loom having a movable drop box on one side thereof, a Weft selector mechanism comprising, in combination, bobbin release means for replacing an empty bobbin on the other side of the loom; movable operating means for actuating said bobbin release means and being movable between an operative position for effecting a bobbin release and an inoperative position, said operating means tending to move to said inoperative position; ac tuating means arranged reciprocable along a predetermined path; drive shaft means adapted to operate the drop box; cam means on said drive shaft means and engaging said actuating means for reciprocating the same in a predetermined sequence with the drop box movement; a trigger lever pivotally connected to said operating means and being turnable between two inoperative end positions and an intermediate operative position located in the path of the actuating means, said operating means tending to move from one of said inoperative end positions to the other of said inoperative end positions; electromagnetic shifting means for shifting said trigger lever from said other inoperative end position to said one inoperative end position of the same and including an electric circuit; movable stop means movable between a holding position engaging said trigger lever and holding the same in said operative position and a releasing position releasing said trigger lever to move into said other inoperative position, said stop means tending to move to said holding position; and feeler means located on said one drop box side of the loom and including contact means connected in said circuit and adapted to be closed by an empty bobbin in the drop box whereby said electromagnetic shifting means are actuated to shift said trigger lever into said one inoperative position from which it moves to said operative position thereof so that said actuating means move through said trigger lever said operating means to said operative position of the same so as to effect a bobbin release.

7. In a loom having a movable drop box on one side thereof, a weft selector mechanism comprising, in combination, bobbin release means for replacing an empty bobbin on the other side of the loom; movable operating lever means for actuating said bobbin release means and being movable between an operative position for efiecting a bobbin release and an inoperative position, said operating lever means tending to move to said inoperative position; actuating lever means pivotally mounted for reciprocation along a predetermined path; drive shaft means adapted to operate the drop box; cam means on said drive shaft means and engaging said actuating lever means for reciprocating the same in a predetermined sequence with the drop box movement; a trigger lever pivotally connected to said operating lever means and being turnable between two inoperative end positions and an intermediate operative position located in the path of the actuating lever means, said operating lever means tending to move from one of said inoperative positions to the other of said inoperative positions; electro-magnetic shifting means for shifting said trigger lever from said other inoperative position to said one inoperative position of the same and including an electric circuit; movable stop means movable between a holding position engaging said trigger lever and holding the same in said operative position, and a releasing position releasing said trigger lever to move into said other inoperative position, said stop means tending to move to said holding position; and feeler means located on said one drop box side of the loom and including contact means connected in said circuit and adapted to be closed by an empty bobbin in the drop box whereby said electro-magnetic shifting means are actuated to shift said trigger lever into said one inoperative position from which it moves to said operative position thereof so that said actuating lever means move through said trigger lever said operating lever means to said operative position of the same so as to effect a bobbin release.

References Cited in the file of this patent UNITED STATES PATENTS 2,056,695 Turner Oct. 6, 1936 2,149,692 Tirrell Mar. 7, 1939 2,358,905 Bergstrom Sept. 26, 1944 

